fixed rvm warning

themes/Soliah.zsh-theme

@@ -32,11 +32,12 @@ function check_git_prompt_info() {
 
 # Determine if we are using a gemset.
 function rvm_gemset() {
-    GEMSET=`rvm gemset list | grep '=>' | cut -b4-`
-    if [[ -n $GEMSET ]]; then
-        echo "%{$fg[yellow]%}$GEMSET%{$reset_color%}|"
-    fi 
-
+    if hash rvm 2>/dev/null; then
+        GEMSET=`rvm gemset list | grep '=>' | cut -b4-`
+        if [[ -n $GEMSET ]]; then
+            echo "%{$fg[yellow]%}$GEMSET%{$reset_color%}|"
+        fi 
+    fi
 }
 
 # Determine the time since last commit. If branch is clean,